The present disclosure relates to a light emitting device, and more particularly, to a light emitting device that is configured to enhance adhesive force between a lead frame and a molding unit by forming a fixing space through the lead frame and integrally forming the molding unit on the top surface of the lead frame and in the fixing space.
Generally, a light emitting device uses a variety of light emitting chips. For example, a light emitting diode (LED) uses an element that generates minority carriers (electrons or holes) injected using a p-n junction of a semiconductor and emits light by recombination of the carriers. The LED consumes less electricity and has several to tens times more service life than the incandescent light bulb or a fluorescent lamp. That is, the LED is excellent in terms of the power consumption and endurance.
Since the LEDs can efficiently emit the light using a low voltage, they have been used for home appliances, electronic display boards, display devices, and a variety of automated machines. Recently, as the devices are getting smaller and slimmer, the LEDs have been made in a surface mount device type so that they can be directly mounted on a printed circuit board. Particularly, a light emitting device that is designed such that a separate insulation substrate is not used but a lead frame is used instead of the insulation substrate and a molding unit is directly formed on the lead frame has been recently proposed.
However, there are limitations due to a structure of the molding unit formed only on a top surface of the lead frame in that a phenomenon where a boundary surface between the lead frame and the molding unit is widened as the molding unit is easily separated from the lead frame by external causes such as increase of ambient temperature during a reflow process occurs.
Accordingly, the light emitting diode and wires enclosed by the molding unit may be damaged by being exposed to air or moisture. In addition, a bending portion may be cut by the separation of the molding unit.